Practicality: Place the alarm on the right ear and open the switch to check if the set alarm is appropriate. When it is not properly positioned, it will sound a "beep" to remind you. Alertme Lifesaver Alert Driver Alertness System.Working principle: Once you can't help but fall asleep, the ear bell will emit a crisp "beep" sound, which makes you feel refreshed to avoid accidents.High quality material: Constructed with high quality ABS material, durable in use. Compact and lightweight, it is easy to carry and use.Unique Design: Exquisite and considerate design, fit for your right ear perfectly.Specification:Material: ABSColor: BlackBattery specifications: AG13X3 (Universal Button Battery) One battery service life is about 6 months - 24 months.Instructions: Switch the anti-sleeping alarm to the "ON" and hang it on your ear. Once you can't help but fall asleep, the ear bell will emit a crisp "beep" sound, which makes you feel refreshed to avoid accidents. It can also be used for students at home, sitting in the wrong position during homework. A beep will sound to remind the students.Package List:1 * Anti-Sleep ReminderNote:1. Open the switch and hang it on your ear. Adjust the angle on your ear according to your sitting position until you adjust to the driving position you are most accustomed to. Unscrew the screws on the cover when changing the battery, and open the rear plate.2. Avoid high temperature and wet storage.Size: 7*5*1.5cmColor: blackProducts include: 1 * Alarm